U.S. patent number 10,419,998 [Application Number 15/350,941] was granted by the patent office on 2019-09-17 for techniques for configuring an advanced receiver based on cell information, channel allocation information, or a device display status.
This patent grant is currently assigned to Qualcomm Incorporated. The grantee listed for this patent is QUALCOMM Incorporated. Invention is credited to Srinivasan Balasubramanian, Vishal Dalmiya, Aziz Gholmieh, Shailesh Maheshwari, Prashant Udupa Sripathi, Yue Yang.
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United States Patent |
10,419,998 |
Yang , et al. |
September 17, 2019 |
Techniques for configuring an advanced receiver based on cell
information, channel allocation information, or a device display
status
Abstract
A method, an apparatus, and a computer program product for
wireless communication are provided. The apparatus may identify a
trigger condition relating to one or more of cell information
regarding a cell to which the apparatus is connected, channel
allocation information regarding the device, or a device display
status of the apparatus. The apparatus may selectively activate or
deactivate an advanced receiver of the apparatus based at least in
part on the trigger condition.
Inventors: |
Yang; Yue (San Diego, CA),
Balasubramanian; Srinivasan (San Diego, CA), Gholmieh;
Aziz (Del Mar, CA), Sripathi; Prashant Udupa (San Jose,
CA), Maheshwari; Shailesh (San Diego, CA), Dalmiya;
Vishal (San Diego, CA) |
Applicant: |
Name |
City |
State |
Country |
Type |
QUALCOMM Incorporated |
San Diego |
CA |
US |
|
|
Assignee: |
Qualcomm Incorporated (San
Diego, CA)
|
Family
ID: |
60084091 |
Appl.
No.: |
15/350,941 |
Filed: |
November 14, 2016 |
Prior Publication Data
|
|
|
|
Document
Identifier |
Publication Date |
|
US 20180139672 A1 |
May 17, 2018 |
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04W
52/0229 (20130101); H04W 52/0258 (20130101); H04W
36/22 (20130101); H04W 52/0254 (20130101); H04W
36/14 (20130101); H04W 88/02 (20130101); H04W
88/08 (20130101); Y02D 70/146 (20180101); Y02D
30/70 (20200801); H04W 88/06 (20130101); H04W
52/0238 (20130101); Y02D 70/00 (20180101); Y02D
70/1262 (20180101); H04W 84/042 (20130101); Y02D
70/1242 (20180101); H04W 84/12 (20130101); Y02D
70/142 (20180101) |
Current International
Class: |
H04W
36/22 (20090101); H04W 36/14 (20090101); H04W
88/02 (20090101); H04W 52/02 (20090101); H04W
84/12 (20090101); H04W 84/04 (20090101); H04W
88/06 (20090101); H04W 88/08 (20090101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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3016447 |
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May 2016 |
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EP |
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2014189461 |
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Nov 2014 |
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WO |
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Other References
International Search Report and Written
Opinion--PCT/US2017/053975--ISA/EPO--dated Dec. 7, 2017. cited by
applicant.
|
Primary Examiner: Thompson, Jr.; Otis L
Attorney, Agent or Firm: Harrity & Harrity,
LLP\Qualcomm
Claims
What is claimed is:
1. A method for wireless communication, comprising: determining, by
a user equipment (UE), a device display status of the UE;
predicting, by the UE, downlink traffic based on the device display
status of the UE; identifying, by the UE, a trigger condition
relating to the downlink traffic; and selectively activating or
deactivating, by the UE, an advanced receiver of the UE based at
least in part on the trigger condition, wherein selectively
activating or deactivating the advanced receiver comprises
activating the advanced receiver in one or more periods when the UE
is predicted to receive the downlink traffic.
2. The method of claim 1, wherein the trigger condition further
relates to cell information regarding a cell to which the UE is
connected; wherein the cell information identifies whether the cell
is associated with a high speed condition; and wherein the advanced
receiver is selectively activated or deactivated based at least in
part on whether the cell is associated with the high speed
condition.
3. The method of claim 1, wherein the trigger condition further
relates to cell information regarding a cell to which the UE is
connected; wherein the cell information identifies whether the cell
is a small cell; and wherein the advanced receiver is selectively
activated or deactivated based at least in part on whether the cell
is a small cell.
4. The method of claim 1, wherein the trigger condition further
relates to cell information regarding a cell to which the UE is
connected; wherein the cell information identifies historical
performance of the cell; and wherein the advanced receiver is
selectively activated or deactivated based at least in part on the
historical performance of the cell.
5. The method of claim 4, wherein the cell information identifies
the historical performance of the cell based at least in part on a
time of day.
6. The method of claim 1, wherein the advanced receiver is
configured based at least in part on cell information identifying a
neighbor cell of a cell to which the UE is connected.
7. The method of claim 1, wherein the trigger condition further
relates to cell information regarding a cell to which the UE is
connected; wherein the cell information identifies a radio access
technology (RAT) to which the UE is connected; and wherein the
advanced receiver is selectively activated or deactivated based at
least in part on the RAT to which the UE is connected.
8. The method of claim 1, wherein the trigger condition further
relates to channel allocation information regarding the UE; wherein
the channel allocation information identifies an estimated
bandwidth allocation associated with a cell, to which the UE is
connected, and determined based at least in part on a noise
estimation; and wherein the advanced receiver is selectively
activated or deactivated based at least in part on the estimated
bandwidth allocation.
9. The method of claim 1, wherein the trigger condition further
relates to channel allocation information regarding the UE; wherein
the channel allocation information identifies a modulation and
coding scheme (MCS) allocation associated with the UE; and wherein
the advanced receiver is selectively activated or deactivated based
at least in part on the MCS allocation.
10. The method of claim 1, wherein the trigger condition further
relates to channel allocation information regarding the UE; wherein
the channel allocation information identifies a traffic arrival
prediction; and wherein the advanced receiver is selectively
activated or deactivated based at least in part on the traffic
arrival prediction.
11. A device for wireless communication, comprising: memory; and
one or more processors coupled to the memory, the memory and the
one or more processors configured to: determine a device display
status of the device; predict downlink traffic based on the device
display status of the device; identify a trigger condition relating
to the downlink traffic; and selectively activate or deactivate an
advanced receiver of the device based at least in part on the
trigger condition, wherein, when selectively activating or
deactivating the advanced receiver, the one or more processors are
configured to activate the advanced receiver in one or more periods
when the device is predicted to receive the downlink traffic.
12. The device of claim 11, wherein the trigger condition further
relates to cell information regarding a cell to which the device is
connected; wherein the cell information identifies whether the cell
is associated with a high speed condition; and wherein the advanced
receiver is selectively activated or deactivated based at least in
part on whether the cell is associated with the high speed
condition.
13. The device of claim 11, wherein the trigger condition further
relates to cell information regarding a cell to which the device is
connected; wherein the cell information identifies whether the cell
is a small cell; and wherein the advanced receiver is selectively
activated or deactivated based at least in part on whether the cell
is a small cell.
14. The device of claim 11, wherein the trigger condition further
relates to cell information regarding a cell to which the device is
connected; wherein the cell information identifies historical
performance of the cell; and wherein the advanced receiver is
selectively activated or deactivated based at least in part on the
historical performance of the cell.
15. The device of claim 11, wherein the advanced receiver is
configured based at least in part on cell information identifying a
neighbor cell of a cell to which the device is connected.
16. The device of claim 11, wherein the trigger condition further
relates to cell information regarding a cell to which the device is
connected; wherein the cell information identifies a radio access
technology (RAT) to which the device is connected; and wherein the
advanced receiver is selectively activated or deactivated based at
least in part on the RAT to which the device is connected.
17. The device of claim 11, wherein the trigger condition further
relates to channel allocation information regarding the device;
wherein the channel allocation information identifies an estimated
bandwidth allocation associated with a cell, to which the device is
connected, and determined based at least in part on a noise
estimation; and wherein the advanced receiver is selectively
activated or deactivated based at least in part on the estimated
bandwidth allocation.
18. The device of claim 11, wherein the trigger condition further
relates to channel allocation information regarding the device;
wherein the channel allocation information identifies a modulation
and coding scheme (MCS) allocation associated with the device; and
wherein the advanced receiver is selectively activated or
deactivated based at least in part on the MCS allocation.
19. The device of claim 11, wherein the trigger condition further
relates to channel allocation information regarding the device;
wherein the channel allocation information identifies a traffic
arrival prediction; and wherein the advanced receiver is
selectively activated or deactivated based at least in part on the
traffic arrival prediction.
20. An apparatus for wireless communication, comprising: means for
determining a device display status of the apparatus; means for
predicting downlink traffic based on the device display status of
the apparatus; means for identifying a trigger condition relating
to the downlink traffic; and means for selectively activating or
deactivating an advanced receiver of the apparatus based at least
in part on the trigger condition, wherein the means for selectively
activating or deactivating the advanced receiver comprise means for
activating the advanced receiver in one or more periods when the
apparatus is predicted to receive the downlink traffic.
21. The apparatus of claim 20, wherein the trigger condition
further relates to cell information regarding a cell to which the
apparatus is connected; wherein the cell information identifies
whether the cell is associated with a high speed condition; and
wherein the means for selectively activating or deactivating the
advanced receiver is configured to selectively activate or
deactivate the advanced receiver based at least in part on whether
the cell is associated with the high speed condition.
22. The apparatus of claim 20, wherein the trigger condition
further relates to cell information regarding a cell to which the
apparatus is connected; wherein the cell information identifies
whether the cell is a small cell; and wherein the means for
selectively activating or deactivating the advanced receiver is
configured to selectively activate or deactivate the advanced
receiver based at least in part on whether the cell is a small
cell.
23. The apparatus of claim 20, wherein the trigger condition
further relates to cell information regarding a cell to which the
apparatus is connected; wherein the cell information identifies
historical performance of the cell; and wherein the means for
selectively activating or deactivating the advanced receiver is
configured to selectively activate or deactivate the advanced
receiver based at least in part on the historical performance of
the cell.
24. The apparatus of claim 20, wherein the trigger condition
further relates to cell information regarding a cell to which the
apparatus is connected; wherein the cell information identifies a
radio access technology (RAT) to which the apparatus is connected;
and wherein the means for selectively activating or deactivating
the advanced receiver is configured to selectively activate or
deactivate the advanced receiver based at least in part on the RAT
to which the apparatus is connected.
25. The apparatus of claim 20, wherein the trigger condition
further relates to channel allocation information regarding the
apparatus; wherein the channel allocation information identifies an
estimated bandwidth allocation associated with a cell, to which the
apparatus is connected, and determined based at least in part on a
noise estimation; and wherein the means for selectively activating
or deactivating the advanced receiver is configured to selectively
activate or deactivate the advanced receiver based at least in part
on the estimated bandwidth allocation.
26. A non-transitory computer-readable medium storing instructions
for wireless communication, the instructions comprising: one or
more instructions that, when executed by one or more processors of
a user equipment (UE), cause the one or more processors to:
determine a device display status of the UE; predict downlink
traffic based on the device display status of the UE; identify a
trigger condition relating to the downlink traffic; and selectively
activate or deactivate an advanced receiver of the UE based at
least in part on the trigger condition, wherein the one or more
instructions to selectively activate or deactivate the advanced
receiver cause the one or more processors to activate the advanced
receiver in one or more periods when the UE is predicted to receive
the downlink traffic.
27. The non-transitory computer-readable medium of claim 26,
wherein the trigger condition further relates to cell information
regarding a cell to which the UE is connected; wherein the cell
information identifies whether the cell is a small cell; and
wherein the advanced receiver is selectively activated or
deactivated based at least in part on whether the cell is a small
cell.
28. The non-transitory computer-readable medium of claim 26,
wherein the trigger condition further relates to cell information
regarding a cell to which the UE is connected; wherein the cell
information identifies historical performance of the cell; and
wherein the advanced receiver is selectively activated or
deactivated based at least in part on the historical performance of
the cell.
29. The non-transitory computer-readable medium of claim 26,
wherein the trigger condition further relates to cell information
regarding a cell to which the UE is connected; wherein the cell
information identifies a radio access technology (RAT) to which the
UE is connected; and wherein the advanced receiver is selectively
activated or deactivated based at least in part on the RAT to which
the UE is connected.
30. The non-transitory computer-readable medium of claim 26,
wherein the trigger condition further relates to channel allocation
information regarding the UE; wherein the channel allocation
information identifies a traffic arrival prediction; and wherein
the advanced receiver is selectively activated or deactivated based
at least in part on the traffic arrival prediction.
Description
BACKGROUND
Field
The present disclosure relates generally to communication systems,
and more particularly, to techniques for configuring an advanced
receiver based on cell information, channel allocation information,
or a device display status.
Background
Wireless communication systems are widely deployed to provide
various telecommunication services such as telephony, video, data,
messaging, and broadcasts. Typical wireless communication systems
may employ multiple-access technologies capable of supporting
communication with multiple users by sharing available system
resources (e.g., bandwidth, transmit power). Examples of such
multiple-access technologies include code division multiple access
(CDMA) systems, time division multiple access (TDMA) systems,
frequency division multiple access (FDMA) systems, orthogonal
frequency division multiple access (OFDMA) systems, single-carrier
frequency division multiple access (SC-FDMA) systems, and time
division synchronous code division multiple access (TD-SCDMA)
systems.
These multiple access technologies have been adopted in various
telecommunication standards to provide a common protocol that
enables different wireless devices to communicate on a municipal,
national, regional, and even global level. An example
telecommunication standard is Long Term Evolution (LTE). LTE is a
set of enhancements to the Universal Mobile Telecommunications
System (UMTS) mobile standard promulgated by Third Generation
Partnership Project (3GPP). LTE is designed to better support
mobile broadband Internet access by improving spectral efficiency,
lowering costs, improving services, making use of new spectrum, and
better integrating with other open standards using OFDMA on the
downlink (DL), SC-FDMA on the uplink (UL), and multiple-input
multiple-output (MIMO) antenna technology. However, as the demand
for mobile broadband access continues to increase, there exists a
need for further improvements in LTE technology. Preferably, these
improvements should be applicable to other multi-access
technologies and the telecommunication standards that employ these
technologies.
A user equipment (UE) may include an advanced receiver (ARx) to
improve physical layer receiver decoding performance and mitigate
interference (e.g., inter-cell interference or intra-cell
interference) using receiver diversity features, such as 4-antenna
reception (4Rx); interference cancellation features, such as Common
Reference Signal Interference Cancellation (CRS-IC); and the
like.
The UE may activate or deactivate the advanced receiver based at
least in part on a difference in a physical layer (e.g., Layer 1 of
the Open System Interconnect (OSI) model) measurement, such as a
reference signal received power (RSRP) measurement, between a
serving cell of the UE and an interfering cell of the UE. However,
when the serving cell is associated with poor quality, the
improvement to decoding performance associated with activating the
advanced receiver may be limited. Also, it may be of limited
benefit to activate the advanced receiver when data being received
or transmitted by the UE is not associated with a high priority or
importance. The advanced receiver consumes battery power of the UE,
and it may be beneficial to selectively deactivate the advanced
receiver to conserve battery power when the benefit of activating
the advanced receiver is limited.
SUMMARY
Aspects described herein may determine whether to activate or
deactivate the advanced receiver using information or measurements
other than an RSRP difference between the serving cell and the
interfering cell. The information or measurements may include, for
example, cell information (e.g., a cell type or high speed
condition of the serving cell, historical performance of the cell,
information identifying a neighbor or interfering cell, a radio
access technology to which the UE is connected, etc.), bandwidth
allocation information (e.g., an estimated bandwidth allocation
based at least in part on a noise estimation or scheduling
information, a traffic arrival prediction, etc.), a device display
status, and/or information determined using the above information
or measurements (e.g., for the UE and/or other UEs or cells). Thus,
battery power of the UE is conserved when the advanced receiver is
deactivated, and reception performance of the UE is preserved or
improved by activating the advanced receiver in situations when the
UE may benefit from activation of advanced receiver.
In an aspect of the disclosure, a method, a device, an apparatus,
and a computer program product are provided.
In some aspects, the method may include identifying, by a UE, a
trigger condition relating to one or more of: cell information
regarding a cell to which the UE is connected; channel allocation
information regarding the UE; or a device display status of the UE.
The method may include selectively activating or deactivating, by
the UE, an advanced receiver of the UE based at least in part on
the trigger condition.
In some aspects, the device may include memory and one or more
processors coupled to the memory. The memory and the one or more
processors may be configured to identify a trigger condition
relating to one or more of: cell information regarding a cell to
which the device is connected, channel allocation information
regarding the device, or a device display status of the device. The
memory and the one or more processors may be configured to
selectively activate or deactivate an advanced receiver of the
device based at least in part on the trigger condition.
In some aspects, the apparatus may include means for identifying a
trigger condition relating to one or more of: cell information
regarding a cell to which the apparatus is connected; channel
allocation information regarding the apparatus; or a device display
status of the apparatus. The apparatus may include means for
selectively activating or deactivating, by the apparatus, an
advanced receiver of the apparatus based at least in part on the
trigger condition.
In some aspects, the computer program product may include a
non-transitory computer-readable medium storing one or more
instructions for wireless communication that, when executed by one
or more processors of a device, cause the one or more processors to
identify a trigger condition relating to one or more of: cell
information regarding a cell to which the UE is connected; channel
allocation information regarding the UE; or a device display status
of the UE. The one or more instructions may cause the one or more
processors to selectively activate or deactivate an advanced
receiver of the UE based at least in part on the trigger
condition.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram illustrating an example of a network
architecture.
FIG. 2 is a diagram illustrating an example of an access
network.
FIG. 3 is a diagram illustrating an example of a DL frame structure
in LTE.
FIG. 4 is a diagram illustrating an example of an UL frame
structure in LTE.
FIG. 5 is a diagram illustrating an example of a radio protocol
architecture for the user and control planes.
FIG. 6 is a diagram illustrating an example of an evolved Node B
and user equipment in an access network.
FIGS. 7A-7F are diagrams illustrating an example system configured
to selectively activate or deactivate an advanced receiver based at
least in part on cell information, channel allocation information,
and/or a device display status.
FIGS. 8A and 8B are diagrams illustrating another example system
configured to selectively activate or deactivate an advanced
receiver based at least in part on cell information, channel
allocation information, and/or a device display status.
FIG. 9 is a flow chart of a method of wireless communication.
FIG. 10 is a conceptual data flow diagram illustrating the data
flow between different modules/means/components in an example
apparatus.
FIG. 11 is a diagram illustrating an example of a hardware
implementation for an apparatus employing a processing system.
DETAILED DESCRIPTION
The detailed description set forth below in connection with the
appended drawings is intended as a description of various
configurations and is not intended to represent the configurations
in which the concepts described herein may be practiced. The
detailed description includes specific details for the purpose of
providing a thorough understanding of various concepts. However, it
will be apparent to those skilled in the art that these concepts
may be practiced without these specific details. In some instances,
well known structures and components are shown in block diagram
form in order to avoid obscuring such concepts.
Several aspects of telecommunication systems will now be presented
with reference to various apparatus and methods. These apparatus
and methods will be described in the following detailed description
and illustrated in the accompanying drawings by various blocks,
modules, components, circuits, steps, processes, algorithms, etc.
(collectively referred to as "elements"). These elements may be
implemented using electronic hardware, computer software, or any
combination thereof. Whether such elements are implemented as
hardware or software depends upon the particular application and
design constraints imposed on the overall system.
By way of example, an element, or any portion of an element, or any
combination of elements may be implemented with a "processing
system" that includes one or more processors. Examples of
processors include microprocessors, microcontrollers, digital
signal processors (DSPs), field programmable gate arrays (FPGAs),
programmable logic devices (PLDs), state machines, gated logic,
discrete hardware circuits, and other suitable hardware configured
to perform the various functionality described throughout this
disclosure. One or more processors in the processing system may
execute software. Software shall be construed broadly to mean
instructions, instruction sets, code, code segments, program code,
programs, subprograms, software modules, applications, software
applications, software packages, routines, subroutines, objects,
executables, threads of execution, procedures, functions, etc.,
whether referred to as software, firmware, middleware, microcode,
hardware description language, or otherwise.
Accordingly, in one or more example embodiments, the functions
described may be implemented in hardware, software, firmware, or
any combination thereof. If implemented in software, the functions
may be stored on or encoded as one or more instructions or code on
a computer-readable medium. Computer-readable media includes
computer storage media. Storage media may be any available media
that can be accessed by a computer. By way of example, and not
limitation, such computer-readable media can comprise a
random-access memory (RAM), a read-only memory (ROM), an
electrically erasable programmable ROM (EEPROM), compact disk ROM
(CD-ROM) or other optical disk storage, magnetic disk storage or
other magnetic storage devices, combinations of the aforementioned
types of computer-readable media, or any other medium that can be
used to store computer executable code in the form of instructions
or data structures that can be accessed by a computer.
FIG. 1 is a diagram illustrating an LTE network architecture 100.
The LTE network architecture 100 may be referred to as an Evolved
Packet System (EPS) 100. The EPS 100 may include one or more user
equipment (UE) 102, an Evolved UMTS Terrestrial Radio Access
Network (E-UTRAN) 104, an Evolved Packet Core (EPC) 110, and an
Operator's Internet Protocol (IP) Services 122. The EPS can
interconnect with other access networks, but for simplicity those
entities/interfaces are not shown. As shown, the EPS provides
packet-switched services, however, as those skilled in the art will
readily appreciate, the various concepts presented throughout this
disclosure may be extended to networks providing circuit-switched
services.
The E-UTRAN includes the evolved Node B (eNB) 106 and other eNBs
108, and may include a Multicast Coordination Entity (MCE) 128. The
eNB 106 provides user and control planes protocol terminations
toward the UE 102. The eNB 106 may be connected to the other eNBs
108 via a backhaul (e.g., an X2 interface). The MCE 128 allocates
time/frequency radio resources for evolved Multimedia Broadcast
Multicast Service (MBMS) (eMBMS), and determines the radio
configuration (e.g., a modulation and coding scheme (MCS)) for the
eMBMS. The MCE 128 may be a separate entity or part of the eNB 106.
The eNB 106 may also be referred to as a base station, a Node B, an
access point, a base transceiver station, a radio base station, a
radio transceiver, a transceiver function, a basic service set
(BSS), an extended service set (ESS), or some other suitable
terminology. The eNB 106 provides an access point to the EPC 110
for a UE 102. Examples of UEs 102 include a cellular phone, a smart
phone, a session initiation protocol (SIP) phone, a laptop, a
personal digital assistant (PDA), a satellite radio, a global
positioning system, a multimedia device, a video device, a digital
audio player (e.g., MP3 player), a camera, a game console, a
tablet, or any other similar functioning device. The UE 102 may
also be referred to by those skilled in the art as a mobile
station, a subscriber station, a mobile unit, a subscriber unit, a
wireless unit, a remote unit, a mobile device, a wireless device, a
wireless communications device, a remote device, a mobile
subscriber station, an access terminal, a mobile terminal, a
wireless terminal, a remote terminal, a handset, a user agent, a
mobile client, a client, or some other suitable terminology. A UE
102, as described herein, may selectively activate or deactivate an
advanced receiver based at least in part on cell information,
channel allocation information, and/or a device display status.
The eNB 106 is connected to the EPC 110. The EPC 110 may include a
Mobility Management Entity (MME) 112, a Home Subscriber Server
(HSS) 120, other MMEs 114, a Serving Gateway 116, a Multimedia
Broadcast Multicast Service (MBMS) Gateway 124, a Broadcast
Multicast Service Center (BM-SC) 126, and a Packet Data Network
(PDN) Gateway 118. The MME 112 is the control node that processes
the signaling between the UE 102 and the EPC 110. Generally, the
MME 112 provides bearer and connection management. All user IP
packets are transferred through the Serving Gateway 116, which
itself is connected to the PDN Gateway 118. The PDN Gateway 118
provides UE IP address allocation as well as other functions. The
PDN Gateway 118 and the BM-SC 126 are connected to the IP Services
122. The IP Services 122 may include the Internet, an intranet, an
IP Multimedia Subsystem (IMS), a PS Streaming Service (PSS), and/or
other IP services. The BM-SC 126 may provide functions for MBMS
user service provisioning and delivery. The BM-SC 126 may serve as
an entry point for content provider MBMS transmission, may be used
to authorize and initiate MBMS Bearer Services within a PLMN, and
may be used to schedule and deliver MBMS transmissions. The MBMS
Gateway 124 may be used to distribute MBMS traffic to the eNBs
(e.g., 106, 108) belonging to a Multicast Broadcast Single
Frequency Network (MBSFN) area broadcasting a particular service,
and may be responsible for session management (start/stop) and for
collecting eMBMS related charging information.
The number and arrangement of devices and networks shown in FIG. 1
are provided as an example. In practice, there may be additional
devices and/or networks, fewer devices and/or networks, different
devices and/or networks, or differently arranged devices and/or
networks than those shown in FIG. 1. Furthermore, two or more
devices shown in FIG. 1 may be implemented within a single device,
or a single device shown in FIG. 1 may be implemented as multiple,
distributed devices. Additionally, or alternatively, a set of
devices (e.g., one or more devices) shown in FIG. 1 may perform one
or more functions described as being performed by another set of
devices shown in FIG. 1.
FIG. 2 is a diagram illustrating an example of an access network
200 in an LTE network architecture. In this example, the access
network 200 is divided into a number of cellular regions (cells)
202. One or more lower power class eNBs 208 may have cellular
regions 210 that overlap with one or more of the cells 202. In such
a case, a UE 102, 206 may use an advanced receiver to improve
downlink performance by mitigating interference associated with the
overlap. The lower power class eNB 208 may be a femto cell (e.g.,
home eNB (HeNB)), pico cell, micro cell, or remote radio head
(RRH). The macro eNBs 204 are each assigned to a respective cell
202 and are configured to provide an access point to the EPC 110
for all the UEs 206 in the cells 202. There is no centralized
controller in this example of an access network 200, but a
centralized controller may be used in alternative configurations.
The eNBs 204 are responsible for all radio related functions
including radio bearer control, admission control, mobility
control, scheduling, security, and connectivity to the serving
gateway 116. An eNB may support one or multiple (e.g., three) cells
(also referred to as a sectors). The term "cell" can refer to the
smallest coverage area of an eNB and/or an eNB subsystem serving a
particular coverage area. Further, the terms "eNB," "base station,"
and "cell" may be used interchangeably herein.
The modulation and multiple access scheme employed by the access
network 200 may vary depending on the particular telecommunications
standard being deployed. In LTE applications, OFDM is used on the
DL and SC-FDMA is used on the UL to support both frequency division
duplex (FDD) and time division duplex (TDD). As those skilled in
the art will readily appreciate from the detailed description to
follow, the various concepts presented herein are well suited for
LTE applications. However, these concepts may be readily extended
to other telecommunication standards employing other modulation and
multiple access techniques. By way of example, these concepts may
be extended to Evolution-Data Optimized (EV-DO) or Ultra Mobile
Broadband (UMB). EV-DO and UMB are air interface standards
promulgated by the 3rd Generation Partnership Project 2 (3GPP2) as
part of the CDMA2000 family of standards and employs CDMA to
provide broadband Internet access to mobile stations. These
concepts may also be extended to Universal Terrestrial Radio Access
(UTRA) employing Wideband-CDMA (W-CDMA) and other variants of CDMA,
such as TD-SCDMA; Global System for Mobile Communications (GSM)
employing TDMA; and Evolved UTRA (E-UTRA), IEEE 802.11 (Wi-Fi),
IEEE 802.16 (WiMAX), IEEE 802.20, and Flash-OFDM employing OFDMA.
UTRA, E-UTRA, UMTS, LTE and GSM are described in documents from the
3GPP organization. CDMA2000 and UMB are described in documents from
the 3GPP2 organization. The actual wireless communication standard
and the multiple access technology employed will depend on the
specific application and the overall design constraints imposed on
the system.
The eNBs 204 may have multiple antennas supporting MIMO technology.
The use of MIMO technology enables the eNBs 204 to exploit the
spatial domain to support spatial multiplexing, beamforming, and
transmit diversity. Spatial multiplexing may be used to transmit
different streams of data simultaneously on the same frequency. The
data streams may be transmitted to a single UE 206 to increase the
data rate or to multiple UEs 206 to increase the overall system
capacity. This is achieved by spatially precoding each data stream
(i.e., applying a scaling of an amplitude and a phase) and then
transmitting each spatially precoded stream through multiple
transmit antennas on the DL. The spatially precoded data streams
arrive at the UE(s) 206 with different spatial signatures, which
enables each of the UE(s) 206 to recover the one or more data
streams destined for that UE 206. On the UL, each UE 206 transmits
a spatially precoded data stream, which enables the eNB 204 to
identify the source of each spatially precoded data stream.
Spatial multiplexing is generally used when channel conditions are
good. When channel conditions are less favorable, beamforming may
be used to focus the transmission energy in one or more directions.
This may be achieved by spatially precoding the data for
transmission through multiple antennas. To achieve good coverage at
the edges of the cell, a single stream beamforming transmission may
be used in combination with transmit diversity. Furthermore, the
UE(s) 206 may selectively perform various advanced receiver
operations to improve downlink performance when channel conditions
are unfavorable, as described in more detail elsewhere herein.
In the detailed description that follows, various aspects of an
access network will be described with reference to a MIMO system
supporting OFDM on the DL. OFDM is a spread-spectrum technique that
modulates data over a number of subcarriers within an OFDM symbol.
The subcarriers are spaced apart at precise frequencies. The
spacing provides "orthogonality" that enables a receiver to recover
the data from the subcarriers. In the time domain, a guard interval
(e.g., cyclic prefix) may be added to each OFDM symbol to combat
inter-OFDM-symbol interference. The UL may use SC-FDMA in the form
of a DFT-spread OFDM signal to compensate for high peak-to-average
power ratio (PAPR).
The number and arrangement of devices and cells shown in FIG. 2 are
provided as an example. In practice, there may be additional
devices and/or cells, fewer devices and/or cells, different devices
and/or cells, or differently arranged devices and/or cells than
those shown in FIG. 2. Furthermore, two or more devices shown in
FIG. 2 may be implemented within a single device, or a single
device shown in FIG. 2 may be implemented as multiple, distributed
devices. Additionally, or alternatively, a set of devices (e.g.,
one or more devices) shown in FIG. 2 may perform one or more
functions described as being performed by another set of devices
shown in FIG. 2.
FIG. 3 is a diagram 300 illustrating an example of a DL frame
structure in LTE. A frame (10 ms) may be divided into 10 equally
sized subframes. Each subframe may include two consecutive time
slots. A resource grid may be used to represent two time slots,
each time slot including a resource block. The resource grid is
divided into multiple resource elements. In LTE, for a normal
cyclic prefix, a resource block contains 12 consecutive subcarriers
in the frequency domain and 7 consecutive OFDM symbols in the time
domain, for a total of 84 resource elements. For an extended cyclic
prefix, a resource block contains 12 consecutive subcarriers in the
frequency domain and 6 consecutive OFDM symbols in the time domain,
for a total of 72 resource elements. Some of the resource elements,
indicated as R 302, 304, include DL reference signals (DL-RS). The
DL-RS include Cell-specific RS (CRS) (also sometimes called common
RS) 302 and UE-specific RS (UE-RS) 304. UE-RS 304 are transmitted
on the resource blocks upon which the corresponding physical DL
shared channel (PDSCH) is mapped. The number of bits carried by
each resource element depends on the modulation scheme. Thus, the
more resource blocks that a UE receives and the higher the
modulation scheme, the higher the data rate for the UE.
As indicated above, FIG. 3 is provided as an example. Other
examples are possible and may differ from what was described above
in connection with FIG. 3.
FIG. 4 is a diagram 400 illustrating an example of an UL frame
structure in LTE. The available resource blocks for the UL may be
partitioned into a data section and a control section. The control
section may be formed at the two edges of the system bandwidth and
may have a configurable size. The resource blocks in the control
section may be assigned to UEs for transmission of control
information. The data section may include all resource blocks not
included in the control section. The UL frame structure results in
the data section including contiguous subcarriers, which may allow
a single UE to be assigned all of the contiguous subcarriers in the
data section.
A UE may be assigned resource blocks 410a, 410b in the control
section to transmit control information to an eNB. The UE may also
be assigned resource blocks 420a, 420b in the data section to
transmit data to the eNB. The UE may transmit control information
(e.g., information associated with scheduling and/or configuring
downlink communications with the UE based at least in part on a
link adaptation process, such as outer link loop adaptation, or
other information) in a physical UL control channel (PUCCH) on the
assigned resource blocks in the control section. The UE may
transmit data or both data and control information in a physical UL
shared channel (PUSCH) on the assigned resource blocks in the data
section. A UL transmission may span both slots of a subframe and
may hop across frequency.
A set of resource blocks may be used to perform initial system
access and achieve UL synchronization in a physical random access
channel (PRACH) 430. The PRACH 430 carries a random sequence and
cannot carry any UL data/signaling. Each random access preamble
occupies a bandwidth corresponding to six consecutive resource
blocks. The starting frequency is specified by the network. That
is, the transmission of the random access preamble is restricted to
certain time and frequency resources. There is no frequency hopping
for the PRACH. The PRACH attempt is carried in a single subframe (1
ms) or in a sequence of few contiguous subframes and a UE can make
a single PRACH attempt per frame (10 ms).
As indicated above, FIG. 4 is provided as an example. Other
examples are possible and may differ from what was described above
in connection with FIG. 4.
FIG. 5 is a diagram 500 illustrating an example of a radio protocol
architecture for the user and control planes in LTE. The radio
protocol architecture for the UE and the eNB is shown with three
layers: Layer 1, Layer 2, and Layer 3. Layer 1 (L1 layer) is the
lowest layer and implements various physical layer signal
processing functions. The L1 layer will be referred to herein as
the physical layer 506. Layer 2 (L2 layer) 508 is above the
physical layer 506 and is responsible for the link between the UE
and eNB over the physical layer 506.
In the user plane, the L2 layer 508 includes a media access control
(MAC) sublayer 510, a radio link control (RLC) sublayer 512, and a
packet data convergence protocol (PDCP) 514 sublayer, which are
terminated at the eNB on the network side. Although not shown, the
UE may have several upper layers above the L2 layer 508 including a
network layer (e.g., IP layer) that is terminated at the PDN
gateway 118 on the network side, and an application layer that is
terminated at the other end of the connection (e.g., far end UE,
server, etc.).
The PDCP sublayer 514 provides multiplexing between different radio
bearers and logical channels. The PDCP sublayer 514 also provides
header compression for upper layer data packets to reduce radio
transmission overhead, security by ciphering the data packets, and
handover support for UEs between eNBs. The RLC sublayer 512
provides segmentation and reassembly of upper layer data packets,
retransmission of lost data packets, and reordering of data packets
to compensate for out-of-order reception due to hybrid automatic
repeat request (HARQ). The MAC sublayer 510 provides multiplexing
between logical and transport channels. The MAC sublayer 510 is
also responsible for allocating the various radio resources (e.g.,
resource blocks) in one cell among the UEs. The MAC sublayer 510 is
also responsible for HARQ operations.
In the control plane, the radio protocol architecture for the UE
and eNB is substantially the same for the physical layer 506 and
the L2 layer 508 with the exception that there is no header
compression function for the control plane. The control plane also
includes a radio resource control (RRC) sublayer 516 in Layer 3 (L3
layer). The RRC sublayer 516 is responsible for obtaining radio
resources (e.g., radio bearers) and for configuring the lower
layers using RRC signaling between the eNB and the UE.
As indicated above, FIG. 5 is provided as an example. Other
examples are possible and may differ from what was described above
in connection with FIG. 5.
FIG. 6 is a block diagram of an eNB 610 in communication with a UE
650 in an access network. In the DL, upper layer packets from the
core network are provided to a controller/processor 675. The
controller/processor 675 implements the functionality of the L2
layer. In the DL, the controller/processor 675 provides header
compression, ciphering, packet segmentation and reordering,
multiplexing between logical and transport channels, and radio
resource allocations to the UE 650 based on various priority
metrics. The controller/processor 675 is also responsible for HARQ
operations, retransmission of lost packets, and signaling to the UE
650.
The transmit (TX) processor 616 implements various signal
processing functions for the L1 layer (i.e., physical layer). The
signal processing functions include coding and interleaving to
facilitate forward error correction (FEC) at the UE 650 and mapping
to signal constellations based on various modulation schemes (e.g.,
binary phase-shift keying (BPSK), quadrature phase-shift keying
(QPSK), M-phase-shift keying (M-PSK), M-quadrature amplitude
modulation (M-QAM)). The coded and modulated symbols are then split
into parallel streams. Each stream is then mapped to an OFDM
subcarrier, multiplexed with a reference signal (e.g., pilot) in
the time and/or frequency domain, and then combined together using
an Inverse Fast Fourier Transform (IFFT) to produce a physical
channel carrying a time domain OFDM symbol stream. The OFDM stream
is spatially precoded to produce multiple spatial streams. Channel
estimates from a channel estimator 674 may be used to determine the
coding and modulation scheme, as well as for spatial processing.
The channel estimate may be derived from a reference signal and/or
channel condition feedback transmitted by the UE 650. In some
aspects, the channel estimates may be used to determine channel
allocation information, and the UE 650 may selectively activate or
deactivate an advanced receiver based at least in part on the
channel allocation information. Each spatial stream may then be
provided to a different antenna 620 via a separate transmitter
618TX. Each transmitter 618TX may modulate an RF carrier with a
respective spatial stream for transmission.
At the UE 650, each receiver 654RX receives a signal through its
respective antenna 652. Each receiver 654RX recovers information
modulated onto an RF carrier and provides the information to the
receive (RX) processor 656. The RX processor 656 implements various
signal processing functions and/or advanced receiver functions
(e.g., multi-antenna reception) of the L1 layer. The RX processor
656 may perform spatial processing on the information to recover
any spatial streams destined for the UE 650. If multiple spatial
streams are destined for the UE 650, they may be combined by the RX
processor 656 into a single OFDM symbol stream. The RX processor
656 then converts the OFDM symbol stream from the time-domain to
the frequency domain using a Fast Fourier Transform (FFT). The
frequency domain signal comprises a separate OFDM symbol stream for
each subcarrier of the OFDM signal. The symbols on each subcarrier,
and the reference signal, are recovered and demodulated by
determining the most likely signal constellation points transmitted
by the eNB 610. These soft decisions may be based on channel
estimates computed by the channel estimator 658. The soft decisions
are then decoded and deinterleaved to recover the data and control
signals that were originally transmitted by the eNB 610 on the
physical channel. The data and control signals are then provided to
the controller/processor 659.
The controller/processor 659 implements the L2 layer. In some
aspects, the controller/processor 659 may implement various
advanced receiver functions, such as interference cancellation. The
controller/processor can be associated with a memory 660 that
stores program codes and data. The memory 660 may be referred to as
a computer-readable medium. In the UL, the controller/processor 659
provides demultiplexing between transport and logical channels,
packet reassembly, deciphering, header decompression, control
signal processing to recover upper layer packets from the core
network. The upper layer packets are then provided to a data sink
662, which represents all the protocol layers above the L2 layer.
Various control signals may also be provided to the data sink 662
for L3 processing. The controller/processor 659 is also responsible
for error detection using an acknowledgement (ACK) and/or negative
acknowledgement (NACK) protocol to support HARQ operations.
In the UL, a data source 667 is used to provide upper layer packets
to the controller/processor 659. The data source 667 represents all
protocol layers above the L2 layer. Similar to the functionality
described in connection with the DL transmission by the eNB 610,
the controller/processor 659 implements the L2 layer for the user
plane and the control plane by providing header compression,
ciphering, packet segmentation and reordering, and multiplexing
between logical and transport channels based on radio resource
allocations by the eNB 610. The controller/processor 659 is also
responsible for HARQ operations, retransmission of lost packets,
and signaling to the eNB 610.
Channel estimates derived by a channel estimator 658 from a
reference signal or feedback transmitted by the eNB 610 may be used
by the TX processor 668 to select the appropriate coding and
modulation schemes, and to facilitate spatial processing. The
spatial streams generated by the TX processor 668 may be provided
to different antenna 652 via separate transmitters 654TX. Each
transmitter 654TX may modulate an RF carrier with a respective
spatial stream for transmission.
The UL transmission is processed at the eNB 610 in a manner similar
to that described in connection with the receiver function at the
UE 650. Each receiver 618RX receives a signal through its
respective antenna 620. Each receiver 618RX recovers information
modulated onto an RF carrier and provides the information to a RX
processor 670. The RX processor 670 may implement the L1 layer.
The controller/processor 675 implements the L2 layer. The
controller/processor 675 can be associated with a memory 676 that
stores program codes and data. The memory 676 may be referred to as
a computer-readable medium. In the UL, the controller/processor 675
provides demultiplexing between transport and logical channels,
packet reassembly, deciphering, header decompression, control
signal processing to recover upper layer packets from the UE 650.
Upper layer packets from the controller/processor 675 may be
provided to the core network. The controller/processor 675 is also
responsible for error detection using an ACK and/or NACK protocol
to support HARQ operations.
The number and arrangement of components shown in FIG. 6 are
provided as an example. In practice, there may be additional
components, fewer components, different components, or differently
arranged components than those shown in FIG. 6. Furthermore, two or
more components shown in FIG. 6 may be implemented within a single
component, or a single component shown in FIG. 6 may be implemented
as multiple, distributed components. Additionally, or
alternatively, a set of components (e.g., one or more components)
shown in FIG. 6 may perform one or more functions described as
being performed by another set of components shown in FIG. 6.
FIGS. 7A-7F are diagrams illustrating an example system configured
to selectively activate or deactivate an advanced receiver based at
least in part on cell information, channel allocation information,
and/or a device display status. As shown in FIG. 7A, example system
700 may include a UE 102 (e.g., which may correspond to one or more
of the UE 102 of FIG. 1, the UE 206 of FIG. 2, the UE 650 of FIG.
6, and/or the like), and an eNB 106 (e.g., which may correspond to
one or more of the eNBs 106, 108 of FIG. 1, the eNBs 204, 208 of
FIG. 2, the eNB 610 of FIG. 6, and/or the like).
As shown in FIG. 7A, and by reference number 702, a connection
between a UE 102 and an eNB 106 may be associated with channel
noise. Channel noise may occur when a channel provided by the eNB
106 is associated with multiple, different connections with various
UEs 102. The quantity and distribution of channel noise in a
channel may permit estimation of characteristics of the channel
bandwidth allocation. For example, channels or sub-channels that
are heavily utilized or heavily scheduled may have more channel
noise than channels or sub-channels that are lightly utilized or
lightly scheduled.
As shown by reference number 704, the UE 102 may determine a
channel noise estimation with regard to the connection with the eNB
106. The UE 102 may determine the channel noise estimation by
scanning frequencies of the channel to identify relative noise
levels of the frequencies, and performing a noise estimation
algorithm using the relative noise levels of the frequencies.
As shown by reference number 706, the UE 102 may estimate a serving
cell scheduling status and/or a channel bandwidth allocation using
the channel noise estimation information. For example, the UE 102
may use a process, such as least-squares channel estimation,
iterative channel estimation, and/or the like, based at least in
part on the channel noise estimation information, to identify the
serving cell scheduling status and/or the channel bandwidth
allocation.
As shown by reference number 708, the UE 102 may determine that the
serving cell scheduling status and/or the channel bandwidth
allocation satisfies a threshold, and may activate an advanced
receiver of the UE 102 based at least in part on the serving cell
scheduling status and/or the channel bandwidth allocation
satisfying the threshold. For example, the threshold may identify a
threshold quantity or ratio of allocated bandwidth. When the
channel bandwidth allocation satisfies the threshold, the UE may
activate the advanced receiver. For example, the advanced receiver
may provide more efficient interference cancellation in a channel
when the channel is heavily utilized or scheduled than when the
channel is lightly utilized or scheduled. By activating the
advanced receiver when the serving cell scheduling status and/or
the channel bandwidth allocation satisfies the threshold, the UE
102 implements interference cancellation when the UE 102 is likely
to benefit most from the interference cancellation.
When the serving cell scheduling status and/or the channel
bandwidth do not satisfy the threshold (e.g., when the channel is
lightly utilized or scheduled), the UE 102 may not activate the
advanced receiver or may deactivate the advanced receiver (e.g.,
when the advanced receiver is already active). By deactivating the
advanced receiver when the advanced receiver is unlikely to improve
reception performance, the UE 102 conserves battery power and
processor resources. In some aspects, the UE 102 may use a link
adaptation process, such as an outer link loop adaptation (OLLA)
process, to signal to the eNB 106 to adjust an MCS or resource
block (RB) allocation of the UE 102. The link adaptation process
may use feedback regarding downlink performance of the connection
between the UE 102 and the eNB 106 to report downlink performance
to the eNB 106, and the eNB may adjust scheduling (e.g., an MCS or
RB allocation) of the UE 102 based at least in part on the downlink
performance. Thus, the UE 102 improves downlink reception of the UE
102 without activating the advanced receiver.
As shown in FIG. 7B, and by reference number 710, the connection
between the UE 102 and the eNB 106 may be associated with a
particular MCS index (e.g., an MCS index of 30). A relatively high
MCS index, corresponding to a complex encoding scheme and/or a high
throughput of the connection, may provide poor downlink performance
when channel quality is low or channel noise is high. A relatively
low MCS index, corresponding to a simple encoding scheme and/or a
low throughput of the connection, may provide better downlink
performance than the relatively high MCS index in such conditions.
The advanced receiver of the UE 102 may provide more benefit in the
case of a relatively low MCS index than in the case of a relatively
high MCS index. For example, the advanced receiver may perform more
effectively for low MCS index values than for high MCS index
values.
As shown by reference number 712, the UE 102 may determine that the
MCS index satisfies a threshold. The threshold may identify an MCS
index value, a modulation and coding scheme, and/or a data rate for
which to activate or deactivate the advanced receiver. A value of
the threshold may be selected based at least in part on a predicted
improvement associated with activating or deactivating the advanced
receiver (e.g., a predicted improvement in reception performance or
battery and/or processor usage).
As shown by reference number 714, the UE 102 may deactivate the
advanced receiver based at least in part on the MCS index
satisfying the threshold (e.g., when the advanced receiver may
provide inadequate improvement of downlink performance due to the
complex encoding scheme and/or high throughput). By deactivating
the advanced receiver when the MCS index satisfies the threshold,
the UE 102 conserves battery power and processor resources that
would otherwise be used to implement the advanced receiver for
limited benefit. As further shown, the UE 102 may indicate, to the
eNB 106, to decrease the MCS index for the UE 102 based at least in
part on link adaptation (e.g., the OLLA process), which may improve
downlink performance of the UE when channel quality is low. In this
way, the UE 102 improves downlink performance without activating
the advanced receiver, which conserves battery power and processor
resources of the UE 102.
As shown in FIG. 7C, and by reference number 716, in some aspects,
the UE 102 may establish a connection with a WiFi access point
(e.g., using a WiFi radio access technology (RAT)). For example, as
shown by reference number the 718, the UE 102 may be camped on the
WiFi access point as a serving cell of the UE 102 (e.g., in the
voice domain or the data domain). As further shown, in such a case,
the UE 102 may not be connected with the eNB 106. For example, the
UE 102 may be isolated from the eNB 106, may not be configured for
cellular data, or the like. In such a case, the advanced receiver
may provide little or no improvement for downlink performance of
the UE 102. For example, the advanced receiver may be configured to
improve cellular reception performance and not WiFi signal
reception performance. Therefore, the drawbacks to activating the
advanced receiver (e.g., processor and/or battery consumption) when
the UE 102 is camped on the WiFi RAT may outweigh the improvements
to downlink performance of the UE 102.
As shown by reference number 720, the UE 102 may deactivate the
advanced receiver based at least in part on establishing the
connection with the WiFi RAT. By deactivating the advanced
receiver, the UE 102 conserves battery and/or processor resources
that would otherwise be used to implement the advanced receiver
when the advanced receiver may provide little or no benefit.
As shown in FIG. 7D, and by reference number 722, in some aspects,
the UE 102 may receive cell information relating to a cell to which
the UE 102 is connected (e.g., a cell provided by eNB 106). Here,
the cell information indicates that the cell is associated with a
high speed train. In some aspects, the UE 102 may determine that
the cell is associated with a high speed train (e.g., based at
least in part on a location and/or a movement speed of the UE 102).
Additionally, or alternatively, the eNB 106 or another UE 102 may
provide, to the UE 102, information indicating that the cell is
associated with a high speed train (e.g., signaling that includes a
high speed train flag). In some aspects, more generally, the UE 102
may identify a high speed condition associated with a cell. For
example, the UE 102 may determine that the UE 102 is associated
with a threshold speed in a particular cell, may determine that
other UEs 102 are associated with the threshold speed in the
particular cell, may receive information from the eNB 106
indicating that the cell is associated with the high speed
condition, or the like.
As shown by reference number 724, the UE 102 may deactivate the
advanced receiver in the cell associated with the high speed train.
For example, when the cell is associated with a high speed train,
UEs 102 moving through the cell may be moving at high speed.
Therefore, the interference cancellation operations performed by
advanced receivers of the UEs 102 may be less effective than in a
cell in which UEs 102 travel at a slower speed (e.g., walking
speed, driving speed, etc.). For example, the interference
cancellation operations may reduce interference based at least in
part on detection of patterns of interference, and the high speed
movement of the UEs 102 may hamper detection of the patterns of
interference, or may obfuscate the patterns of interference. By
deactivating the advanced receiver in the cell associated with the
high speed condition, the UE 102 conserves processor resources and
battery power that would otherwise be used to activate the advanced
receiver for limited benefit.
As shown in FIG. 7E, and by reference number 726, in some aspects,
the UE 102 may connect with a small cell (e.g., a micro cell, a
pico cell, a femto cell, etc.). Here, as shown, the eNB 106 is a
home eNB 106 that provides a small cell. In some aspects, a
particular configuration of interference cancellation (e.g., common
reference signal interference cancellation (CRS-IC) may perform
more effectively in a small cell as compared to a large cell (e.g.,
a macro cell or regular cell). For example, CRS-IC may be performed
for a colliding case (e.g., when the common reference signal of the
dominant or serving cell and the interfering cell are overlapped)
or for a non-colliding case (e.g., when the common reference signal
of the dominant or serving cell and the interfering cell do not
overlap). The colliding case of CRS-IC may provide better downlink
performance for a small cell, and the non-colliding case of CRS-IC
may provide better downlink performance for a large cell.
As shown by reference number 728, the UE 102 may determine that the
UE 102 is connected to a small cell. As shown, the UE 102 may
accordingly activate an advanced receiver of the UE 102, and may
configure interference cancellation of the advanced receiver. Here,
the UE 102 configures the CRS-IC process for the colliding case
based at least in part on the UE 102 being connected to a small
cell. In a case where the UE 102 is connected to a macro cell, the
UE 102 may selectively activate the advanced receiver (e.g.,
according to one or more other factors described herein) and may
configure the CRS-IC process for the non-colliding case.
As shown in FIG. 7F, and by reference number 730, in some aspects,
the UE 102 may determine that a device display of the UE 102 is
powered off. The device display status of the UE 102 may indicate
the relative importance or likelihood of occurrence of data en
route to or from the UE 102. For example, when the UE device
display is powered off, data en route to the UE 102 may be likely
to be relatively unimportant (e.g., background data, etc.).
Additionally, or alternatively, when the UE device display is
powered on, data en route to the UE 102 may be likely to be
relatively important. For example, when the UE device display is
powered on, the data may have been requested by a user, may be
related to web browsing, streaming, or gaming content, and/or the
like. As further shown, the UE 102 may activate the advanced
receiver when the UE device display is powered on. In this way, the
UE 102 improves downlink performance when the data en route to the
UE 102 is likely to be important (e.g., when the UE device display
is powered on).
As shown by reference number 732, the UE 102 may determine that the
UE device display is powered off. Accordingly, the UE 102 may
deactivate the advanced receiver. By deactivating the advanced
receiver when the UE device display is powered off, the UE 102
conserves processor and battery resources that would otherwise be
used to operate the advanced receiver for unimportant and/or sparse
data.
As shown by reference number 734, in some aspects, the UE 102 may
predict downlink traffic using the device display status. For
example, the UE 102 may determine that downlink traffic is likely
to arrive a particular length of time after the UE device display
is powered on. Additionally, or alternatively, the UE 102 may
determine that downlink traffic is unlikely to be received within a
particular length of time after the UE device display is powered
off. In some aspects, the UE 102 may predict the downlink traffic
based at least in part on additional or alternative factors, such
as past behavior of a user of the UE 102, a traffic type received
or transmitted by the UE 102, motion information associated with
the UE 102, a channel quality report received by the UE 102, and/or
the like.
As further shown, the UE 102 may selectively activate the advanced
receiver based at least in part on the predicted downlink traffic.
For example, the UE 102 may activate the advanced receiver in
periods when the UE 102 is predicted to receive downlink traffic,
and may deactivate the advanced receiver in periods when the UE 102
is predicted not to receive downlink traffic. In this way, the UE
102 conserves battery and processor resources in the periods when
the advanced receiver is deactivated, and improves reception of the
downlink traffic in the periods when the advanced receiver is
activated. In some aspects, the UE 102 may predict the downlink
traffic based at least in part on the UE device display status.
Additionally, or alternatively, the UE 102 may predict the downlink
traffic independently of the UE device display status.
As indicated above, FIGS. 7A-7F are provided as examples. Other
examples are possible and may differ from what was described with
regard to FIGS. 7A-7F.
FIGS. 8A and 8B are diagrams illustrating another example system
configured to selectively activate or deactivate an advanced
receiver based at least in part on cell information, channel
allocation information, and/or a device display status. As shown in
FIGS. 8A and 8B, example system 800 may include a UE 102 (e.g.,
which may correspond to one or more of the UE 102 of FIG. 1, the UE
206 of FIG. 2, the UE 650 of FIG. 6, and/or the like), and an eNB
106 (e.g., which may correspond to one or more of the eNBs 106, 108
of FIG. 1, the eNBs 204, 208 of FIG. 2, the eNB 610 of FIG. 6,
and/or the like).
As shown in FIG. 8A, and by reference number 802, the UE 102 may
establish a connection with a serving cell 802 provided by eNB
106-1. In some aspects, the serving cell 802 may include a long
dwell cell of the UE 102 (e.g., a cell that has maintained a
connection with the UE 102 for a threshold length of time). As
shown by reference number 802, the UE 102 may establish a
connection with a neighbor cell 804 provided by eNB 106-2.
As shown by reference number 806, the UE 102 may receive cell
information associated with the serving cell 802 and/or the
neighbor cell 804. As shown, in some aspects, the cell information
may include information identifying historical performance of the
cells. The information identifying historical performance may
identify, for example, throughput of a cell, a quantity of dropped
calls experienced by UEs 102 connected to the cell, historical
channel information associated with the cell, historical call
quality information associated with the cell, and/or the like. As
further shown, in some aspects, the cell information may include
time of day performance information. The time of day performance
information may correlate the information identifying historical
performance with particular times of day.
As further shown, in some aspects, the cell information may include
neighbor cell information. For example, when the serving cell 802
is a long dwell cell of the UE 102, the UE 102 may determine
neighbor cell information associated with the neighbor cell 804.
The neighbor cell information may include any information that is
used to improve an interference cancellation process of the
advanced receiver, such as information identifying channels
provided by the neighbor cell 804, information identifying timing
of synchronization signals transmitted by the neighbor cell 804,
information identifying a location of the neighbor cell 804,
information identifying a cell type of the neighbor cell, and/or
the like.
In some aspects, the UE 102 may determine the cell information. For
example, the UE 102 may determine the cell information by obtaining
the cell information from the eNBs 106-1 and 106-2. Additionally,
or alternatively, the UE 102 may determine the cell information by
observing historical performance of the cells 802 and/or 804 (e.g.,
with regard to calls placed or received via the cells 802 and/or
804, data transmitted or received via the cells 802 and/or 804,
signal strength or channel quality provided by the cells 802 and/or
804, etc.). In some aspects, the UE 102 may receive or access the
cell information (e.g., from another UE 102, from a network entity,
etc.). For example, a network entity may determine the cell
information, and may store and/or provide the cell information to
the UE 102.
As shown in FIG. 8B, and by reference number 808, the UE 102 may
determine whether to activate or deactivate the advanced receiver
based at least in part on the cell information. Here, the UE 102
determines that the cell information indicates poor historical
performance of the cell (e.g., the serving cell 802 and/or the
neighbor cell 804) at peak hours (e.g., hours of peak usage of the
serving cell 802 and/or the neighbor cell 804). Accordingly, the UE
102 determines to activate the advanced receiver at the peak hours.
In this way, the UE 102 improves reception in conditions identified
by the historical cell information associated with the serving cell
802 and/or the neighbor cell 804, which improves performance of the
UE 102.
As shown by reference number 810, in some aspects, the UE 102 may
configure interference cancellation of the advanced receiver based
at least in part on the neighbor cell information. For example,
when the UE 102 establishes a connection with the serving cell 802,
the UE 102 may configure the interference cancellation based at
least in part on the neighbor cell information associated with the
neighbor cell 804. In some aspects, the UE 102 may store the
neighbor cell information at a first time corresponding to a first
connection with the serving cell 802 and/or the neighbor cell 804,
and may use the neighbor cell information at a second time
corresponding to a second connection with the serving cell 802. By
configuring the interference cancellation based at least in part on
the neighbor cell information, the UE 102 improves performance of
the interference cancellation and thus improves downlink
performance.
While implementations described in connection with FIGS. 7A-7F and
8A-8B are described in the context of activating or deactivating an
advanced receiver, any of the implementations of FIGS. 7A-7F and
8A-8B may additionally or alternatively be implemented by
reconfiguring an advanced receiver. For example, the UE 102 may
increase or decrease processor or battery resources allotted to the
advanced receiver based at least in part on one or more of the
above trigger conditions. Additionally, or alternatively, the UE
102 may increase a quantity of receiver antennas (e.g., from 2Rx to
4Rx, etc.). Additionally, or alternatively, the UE 102 may activate
one or more aspects of the advanced receiver (e.g., interference
cancellation, multi-antenna reception, etc.), and may deactivate
one or more other aspects of the advanced receiver.
While some of the implementations described in connection with
FIGS. 7A-7F and 8A-8B may describe the trigger conditions in
isolation from each other (e.g., activating or deactivating the
advanced receiver in response to a value of a single trigger
condition), in some aspects, the UE 102 may determine whether to
activate or deactivate the advanced receiver based at least in part
on a combination of values of the above trigger conditions. For
example, the UE 102 may assign weights to the above trigger
conditions, and may combine weighted values of the trigger
conditions to determine whether to activate or deactivate the
advanced receiver.
In some aspects, the UE 102 may use other trigger conditions in
addition to or independently of the trigger conditions above. The
other trigger conditions may include, for example, a value of a
HARQ packet error rate (e.g., the UE 102 may activate the advanced
receiver when the HARQ packet error rate satisfies a threshold), a
value of a real-time transport protocol (RTP) erasure rate or a TCP
duplicate ACK number (e.g., the UE 102 may activate the advanced
receiver when the RTP erasure rate or the TCP duplicate ACK number
satisfies a threshold), a traffic type (e.g., may activate or
deactivate the advanced receiver based at least in part on the
traffic type), a battery status of the UE 102 (e.g., may deactivate
the advanced receiver when the battery of the UE 102 is low), or
the like.
In some aspects, the UE 102 may determine whether to activate or
deactivate the advanced receiver based at least in part on
information identifying past improvements in performance, processor
usage, and/or battery usage associated with activating or
deactivating the advanced receiver in response to one or more
trigger conditions. For example, the UE 102 may identify a state of
one or more trigger conditions, and may identify information
identifying past improvements in performance associated with
activating or deactivating the advanced receiver in response to the
state of the one or more trigger conditions. The UE 102 may
activate (or deactivate) the advanced receiver when the information
identifying the past improvements satisfies a threshold, and may
not activate (or deactivate) the advanced receiver when the
information identifying the past improvements does not satisfy the
threshold.
In some aspects, the UE 102 may receive or determine information
indicating whether the advanced receiver should be activated or
deactivated based at least in part on an algorithm, such as a
machine learning algorithm, or the like. For example, the machine
learning algorithm may be used to train a model based at least in
part on the information identifying the past improvements in
performance and trigger conditions associated with the past
improvements in performance. The model may receive, as input,
information identifying trigger conditions, and may output a
predicted improvement in performance associated with the trigger
conditions. The UE 102 may selectively activate or deactivate the
advanced receiver based on the predicted improvement in
performance.
In some aspects, the UE 102 may obtain information indicating a
result of activating deactivating the advanced receiver (e.g.,
based at least in part on values of the trigger conditions
described above). The UE 102 may use the information indicating the
result to determine whether the activation or deactivation of the
advanced receiver was optimal. The UE 102 may map information
indicating whether the activation or deactivation was optimal with
the collected metrics, and may use such information to bias the
decision of whether to activate or deactivate the advanced receiver
on future occasions (e.g., by comparing the collected metrics of
the mapped information to newly determined values of one or more
trigger conditions). In this way, the UE 102 may perform online
learning based on feedback regarding the decision of whether to
activate or deactivate the advanced receiver.
As indicated above, FIGS. 8A and 8B are provided as examples. Other
examples are possible and may differ from what was described with
regard to FIGS. 8A and 8B.
FIG. 9 is a flow chart 900 of a method of wireless communication.
The method may be performed by a UE (e.g., which may correspond to
one or more of the UE 102 of FIG. 1, the UE 206 of FIG. 2, the UE
650 of FIG. 6, the apparatus 1002/1002', and/or the like).
As shown in FIG. 9, in some aspects, process 900 may include
identifying a trigger condition relating to one or more of cell
information regarding a cell to which the UE is connected, channel
allocation information regarding the UE, or a device display status
of the UE (block 910). For example, the UE may identify a trigger
condition based at least in part on information determined or
received by the UE. In some aspects, the UE (e.g., the identifying
component 1008, as described below) may identify a trigger
condition based at least in part on a single one of the cell
information, the channel allocation information, or the device
display status. In some aspects, the UE (e.g., the identifying
component 1008, as described below) may identify a trigger
condition based at least in part on a combination of two or more of
the cell information, the channel allocation information, and/or
the device display status.
In some aspects, the UE may identify the trigger condition using
information determined by the UE. For example, the UE may determine
a device display status of the UE, and may identify the trigger
condition according to the device display status. In some aspects,
the UE may identify the trigger condition using information
determined by another device, such as a base station or another UE.
For example, the other device may determine predicted traffic
information, a predicted improvement of activating or deactivating
the advanced receiver, and/or the like, and may provide such
information to the UE. The UE may selectively activate or
deactivate the advanced receiver based at least in part on the
information.
Additionally, or alternatively, the UE may determine that a cell is
associated with a high speed condition (e.g., based at least in
part on a speed of the UE and/or of one or more other UEs near the
UE), and may identify the trigger condition according to the high
speed condition. Additionally, or alternatively, the UE may
identify a channel bandwidth allocation based at least in part on
determining noise estimation information for a channel associated
with the UE, and may identify the trigger condition according to
the channel bandwidth allocation.
Additionally, or alternatively, the UE may determine historical
cell information regarding historical performance of a cell (e.g.,
historical performance with regard to downlink traffic transmitted
via the cell, time of day information associated with the cell,
etc.), and may identify the trigger condition according to the
historical cell information. Additionally, or alternatively, the UE
may determine that a cell to which the UE is connected is a small
cell, and may identify the trigger condition based at least in part
on the cell being a small cell.
In some aspects, the UE may identify the trigger condition based at
least in part on received information. For example, the UE may
receive channel allocation information, such as a MCS index or
scheduling information associated with downlink traffic of the UE,
and may identify the trigger condition according to the MCS index.
Additionally, or alternatively, the UE may receive historical cell
information (e.g., from an eNB or base station, from a network
device that stores historical cell information, from another UE,
etc.), and may identify the trigger condition according to the
historical cell information.
As shown in FIG. 9, in some aspects, process 900 may include
selectively activating or deactivating an advanced receiver of the
UE based at least in part on the trigger condition (block 920). For
example, the UE may selectively activate or deactivate an advanced
receiver of the UE based at least in part on the trigger condition.
In some aspects, the UE may configure the advanced receiver based
at least in part on the trigger condition. For example, the UE may
receive or determine neighbor cell information associated with a
neighbor cell of a serving cell (e.g., a long dwell cell of the
UE), and may configure an interference cancellation operation based
at least in part on the neighbor cell information. As another
example, the UE may determine whether a cell is a small cell, and
may configure an interference cancellation operation based at least
in part on whether the cell is a small cell (e.g., may use a
colliding mode for small cells, and may use a non-colliding mode
for regular or large cells).
In some aspects, the UE may deactivate the advanced receiver when a
cell is associated with a high speed condition, and may activate
the advanced receiver when the cell is not associated with the high
speed condition. Additionally, or alternatively, the UE may
activate the advanced receiver when the cell is associated with
historically poor performance (e.g., based at least in part on
historical cell information and/or time of day information that
satisfies one or more thresholds with regard to performance of the
cell), and may deactivate the advanced receiver when the cell is
not associated with historically poor performance.
Additionally, or alternatively, the UE may deactivate the advanced
receiver when the UE is connected to or camped on a WiFi RAT, and
may activate the advanced receiver when the UE is connected to or
camped on an LTE RAT. Additionally, or alternatively, the UE may
activate the advanced receiver when an estimated bandwidth
allocation indicates that a channel associated with the UE is
heavily scheduled, and may deactivate the advanced receiver when
the estimated bandwidth allocation indicates that the channel is
not heavily scheduled.
Additionally, or alternatively, the UE may deactivate the advanced
receiver when an MCS allocation of the UE satisfies a threshold
(e.g., when the MCS allocation is associated with a sufficiently
complex modulation and coding scheme and/or a sufficiently high
throughput), and may activate the advanced receiver when the MCS
allocation does not satisfy the threshold. Additionally, or
alternatively, the UE may determine a traffic arrival prediction.
The UE may activate the advanced receiver at times when traffic is
predicted to arrive (e.g., particular traffic, such as high
priority traffic, high volumes of traffic, etc.), and may
deactivate the advanced receiver at other times.
Although FIG. 9 shows example blocks of a method of wireless
communication, in some aspects, the method may include additional
blocks, fewer blocks, different blocks, or differently arranged
blocks than those shown in FIG. 9. Additionally, or alternatively,
two or more blocks shown in FIG. 9 may be performed in
parallel.
FIG. 10 is a conceptual data flow diagram 1000 illustrating the
data flow between different modules/means/components in an example
apparatus 1002. The apparatus 1002 may be a UE (e.g., which may
correspond to one or more of the UE 102 of FIG. 1, the UE 206 of
FIG. 2, the UE 650 of FIG. 6, or the like). The apparatus 1002
includes a receiving component 1004, an advanced receiver component
1006, an identifying component 1008, an activating/deactivating
component 1010, a storage component 1012, and a transmission
component 1014.
The reception component 1004 may receive data 1016, which may
include information from an eNB 1018 (e.g., which may correspond to
the eNBs 106, 108 of FIG. 1, the eNBs 204, 208 of FIG. 2, the eNB
610 of FIG. 6, or the like). For example, the reception component
may receive information described in connection with FIGS. 7A-9,
such as downlink traffic, channel allocation information, cell
information, or the like. As shown, the reception component may
provide data 1016 as output to the advanced receiver component 1006
(e.g., as data 1020). In some aspects, the reception component may
provide the data 1016 as output to the identifying component 1008
(e.g., after processing the data and/or as data 1022, when the
advanced receiver component 1006 does not process the data
1016).
The advanced receiver component 1006 may receive data 1020 from the
reception component. The advanced receiver component 1006 may
process data 1020 as described elsewhere herein. The advanced
receiver component 1006 may provide processed data to one or more
components of the apparatus 1002 (e.g., the identifying component
1008 as data 1024, a processor of the apparatus 1002, or another
component).
The identifying component 1008 may receive data 1022/1024, and may
identify a trigger condition based at least in part on the data
1022/1024. In some aspects, the identifying component 1008 may
receive data 1026 (e.g., historical cell information, neighbor cell
information, etc.) from the storage component 1012, and may
identify the trigger condition based at least in part on the data
1026. The storage component 1012 may receive the data 1026 from the
identifying component 1008 or another component, and may store the
data 1026 for use by the identifying component 1008 to identify
trigger conditions. The identifying component 1008 may output data
1028 to the activating/deactivating component 1010. The data 1028
may indicate whether to activate, deactivate, and/or configure the
advanced receiver component 1006. The activating/deactivating
component may provide data 1030 to the advanced receiver component
1006 to cause the advanced receiver component 1006 to be
selectively activated or deactivated based at least in part on the
data 1028. The advanced receiver component 1006 may be activated,
deactivated, or configured according to the data 1030.
In some aspects, the identifying component 1008 may provide data
1032 to the transmission component 1014. The data 1032 may identify
information to be provided to the eNB 1018 (e.g., information
associated with a link adaptation value, etc.). The transmission
component 1014 may transmit the data 1032 as data 1034 to the eNB
1018.
The apparatus 1002 may include additional components that perform
each of the blocks of the algorithm in the aforementioned flow
charts of FIG. 9. As such, each block in the aforementioned flow
charts of FIG. 9 may be performed by a component and the apparatus
1002 may include one or more of those components. The components
may be one or more hardware components specifically configured to
carry out the stated processes/algorithm, implemented by a
processor configured to perform the stated processes/algorithm,
stored within a computer-readable medium for implementation by a
processor, or some combination thereof.
FIG. 11 is a diagram 1100 illustrating an example of a hardware
implementation for an apparatus 1002' employing a processing system
1104. The apparatus 1002' may be a UE (e.g., which may correspond
to one or more of the UE 102 of FIG. 1, the UE 206 of FIG. 2, the
UE 650 of FIG. 6, or the like).
In some aspects, the processing system 1104 may be implemented with
a bus architecture, represented generally by the bus 1106. The bus
1106 may include any number of interconnecting buses and bridges
depending on the specific application of the processing system 1104
and the overall design constraints. The bus 1106 links together
various circuits including one or more processors and/or hardware
modules, represented by the processor 1108, the components 1004,
1006, 1008, 1010, 1012, and 1014, and the computer-readable
medium/memory 1110. The bus 1106 may also link various other
circuits such as timing sources, peripherals, voltage regulators,
and power management circuits, which are well known in the art, and
therefore, will not be described any further.
The processing system 1104 may be coupled to a transceiver 1112.
The transceiver 1112 is coupled to one or more antennas 1114. The
transceiver 1112 provides a means for communicating with various
other apparatus over a transmission medium. The transceiver 1112
receives a signal from the one or more antennas 1114, extracts
information from the received signal, and provides the extracted
information to the processing system 1104, specifically the
reception component 1004. In addition, the transceiver 1112
receives information from the processing system 1104, specifically
the transmission component 1014, and based on the received
information, generates a signal to be applied to the one or more
antennas 1114. The processing system 1104 includes a processor 1108
coupled to a computer-readable medium/memory 1110. The processor
1108 is responsible for general processing, including the execution
of software stored on the computer-readable medium/memory 1110. The
software, when executed by the processor 1108, causes the
processing system 1104 to perform the various functions described
supra for any particular apparatus. The computer-readable
medium/memory 1110 may also be used for storing data that is
manipulated by the processor 1108 when executing software. The
processing system further includes at least one of the components
1004, 1006, 1008, 1010, 1012, and/or 1014. The components may be
software components running in the processor 1108, resident/stored
in the computer readable medium/memory 1110, one or more hardware
modules coupled to the processor 1108, or some combination thereof.
The processing system 1104 may be a component of the UE 650 and may
include the memory 660 and/or at least one of the TX processor 668,
the RX processor 656, and the controller/processor 659.
In one configuration, the apparatus 1002/1002' for wireless
communication includes means for identifying a trigger condition
relating to one or more of cell information regarding a cell to
which the apparatus is connected, channel allocation information
regarding the apparatus, or a device display status of the
apparatus; and means for selectively activating or deactivating, by
the apparatus, an advanced receiver of the apparatus based at least
in part on the trigger condition. The aforementioned means may be
one or more of the aforementioned modules of the apparatus 1002
and/or the processing system 1104 of the apparatus 1002' configured
to perform the functions recited by the aforementioned means. As
described supra, the processing system 1104 may include the TX
Processor 668, the RX Processor 656, and the controller/processor
659. As such, in one configuration, the aforementioned means may be
the TX Processor 668, the RX Processor 656, and the
controller/processor 659 configured to perform the functions
recited by the aforementioned means.
It is understood that the specific order or hierarchy of blocks in
the processes/flow charts disclosed is an illustration of exemplary
approaches. Based upon design preferences, it is understood that
the specific order or hierarchy of blocks in the processes/flow
charts may be rearranged. Further, some blocks may be combined or
omitted. The accompanying method claims present elements of the
various blocks in a sample order, and are not meant to be limited
to the specific order or hierarchy presented.
The previous description is provided to enable any person skilled
in the art to practice the various aspects described herein.
Various modifications to these aspects will be readily apparent to
those skilled in the art, and the generic principles defined herein
may be applied to other aspects. Thus, the claims are not intended
to be limited to the aspects shown herein, but is to be accorded
the full scope consistent with the language claims, wherein
reference to an element in the singular is not intended to mean
"one and only one" unless specifically so stated, but rather "one
or more." The word "exemplary" is used herein to mean "serving as
an example, instance, or illustration." Any aspect described herein
as "exemplary" is not necessarily to be construed as preferred or
advantageous over other aspects. Unless specifically stated
otherwise, the term "some" refers to one or more. Combinations such
as "at least one of A, B, or C," "at least one of A, B, and C," and
"A, B, C, or any combination thereof" include any combination of A,
B, and/or C, and may include multiples of A, multiples of B, or
multiples of C. Specifically, combinations such as "at least one of
A, B, or C," "at least one of A, B, and C," and "A, B, C, or any
combination thereof" may be A only, B only, C only, A and B, A and
C, B and C, or A and B and C, where any such combinations may
contain one or more member or members of A, B, or C. All structural
and functional equivalents to the elements of the various aspects
described throughout this disclosure that are known or later come
to be known to those of ordinary skill in the art are expressly
incorporated herein by reference and are intended to be encompassed
by the claims. Moreover, nothing disclosed herein is intended to be
dedicated to the public regardless of whether such disclosure is
explicitly recited in the claims. No claim element is to be
construed as a means plus function unless the element is expressly
recited using the phrase "means for."
* * * * *